Surely this management of expectations is there in pretty much any activity in a relationship.
I have two passions in my life (three if you include my wife), aviation and martial arts.
My wife is fascinated by aviation, both the technical aspects (she's an engineer) and quite likes going on trips so long as:-
(a) turbulence is minimal
(b) the aeroplane has doors, a windshield, and a cabin heater
(c) she has her camera.
I can handle that, and have learned that telling anecdotes involving engine failures from failed loops in vintage aeroplanes in her hearing is unwise. I also just smiled and signed the life insurance policy that she insisted upon.
In martial arts, she also shares my fascination - but given a choice of a 2 hour hard training session, or a 2 hour technical lecture on MA history, she'll take the latter. She also is much happier on her feet with a sword in her hand, than grappling on the floor in a dojo. So we do sword based stuff together, and I go off and teach Jiu Jitsu on my own. Not a problem either.
All about understanding the person you share your life with and their personal motivations really.
G